April 28, 2013
The activity: Care of trees in springtime.
Why: Trees are likely the most valuable living thing in your landscape. Their age and size might make them irreplaceable. Trees can save you money on heating and cooling by providing shade and protection from wind. They cool ambient air through transportation, absorb carbon dioxide, give off oxygen, mitigate urban noise and provide habitat for birds and wildlife.
Established trees might seem self-sufficient, but arboriculturists agree that healthy trees don’t just happen. By understanding and addressing the seasonal needs of trees, your trees will continue to be healthy.
How: Here are some important steps to tree care:
Step 1: Cleaning up
• Remove any decorations or lights from trees as they might cause girdling.
• Remove any protective winter wraps around trunks. If a tree has been staked for more than 2 years, remove all ties from the trunk.
• Rake and gather debris that collected beneath trees over winter, such as twigs, leaves and fruit. Sanitation is important to reduce diseases and possible pest insects.
Step 2: Roots and mulching
• A healthy tree needs healthy roots, which require air in the soil. If soil is compacted in the root zone, air pockets won’t be available to the roots. The root zone for an established tree extends three to five times beyond the drip line of the branches.
• Apply mulch 3-4 inches deep to enhance moisture retention and weed control while minimizing foot traffic. Mulch should be applied in a circular pattern that extends 2-4 feet from the trunk. On a young tree, this will be to the dripline. As the tree matures, it is not necessary to expand to the dripline.
• Keep mulch 6 inches from the trunk. Never pile chips against the trunk because wet chips can lead to bark decay.
• For groups of trees, consider creating mulch beds around the entire area to protect trunks and the root system. This will create a pleasant “forest” feature.
Step 3: Watering
• Apply water so it moistens the soil to a depth of a foot. Saturate soil around the tree within the drip line. For evergreens, water 3-5 feet beyond the drip line on all sides.
• Water established trees once a week between April and September. Newly planted trees might require more watering. Take any rain into account. A rule of thumb for watering established trees is 10 gallons per inch of diameter at each watering.
Step 4: Inspecting the tree
• Look for signs of stress in your tree. To assess stress, know the average rate of growth for that species and then examine the terminal twigs to determine the amount of growth over the past several years. Trees with dramatically reduced growth rates are a concern.
• Before leaves appear, walk around the tree and inspect the root zone, tree trunks and branches, looking for signs of disease or damage including cankers, lesions, dripping sap and evidence of decay.
• Damage might be caused by humans (lawn mowers, weed eaters, bad pruning cuts, etc.) as well as animals.
• Evidence of decay can indicate a hazardous tree. A drum-like hollow sound when the trunk is tapped or evidence of decay inside large pruning cuts can indicate weak branches and trunks. If you spot something that makes you feel uncertain about the safety of a tree, contact local certified arborists.
Step 5: Pruning
• The ideal time to prune most trees is during winter dormancy. Go online for a guide to proper pruning techniques (cmg.colostate.edu/gardennotes.shtml).
• Remove any dead, damaged or broken branches.
• Prune rubbing and crossing branches, as well as branches that grow toward the interior.
Step 6: Insects and diseases
Insects and diseases account for less than 20 percent of landscape plant problems. Look for symptoms, such as are the twigs or branches becoming discolored and/or dying. Determine if symptoms are found on a variety of trees or only affecting a specific tree. Finally, check out the CSU web site for additional information (ext.colostate.edu/pubs/pubs.html).
When: This cleanup process is ideal during spring.
What’s needed: Rake, shovel, spade, trash bags, lopper, hand pruner, pole pruner, watering device, hose or 5 gallon bucket, wheel barrow and a compost pile.
When you have questions, call the Master Gardener Volunteer Help Desk at 520-7684 or email CSUmg2@
elpasoco.com. Volunteers are available 9 a.m.-noon Monday through Friday.